Expert Witness. WILLIAM P. MANTLE and JOSELYNE CHENANE

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1 Expert Witness WILLIAM P. MANTLE and JOSELYNE CHENANE An expert witness is a person acknowledged by a court to have expertise in a given field or on a topic. These experts provide their professional opinions as testimony to a case in order to provide jurors and judges with information an average person would not possess. For centuries, judges have asked experts for their advice on legal matters, but it was not until Folkes v. Chadd in 1782 that an expert witness was called upon to present evidence to a jury (Anderson 1987). In the United States, an expert witness, as described by Rule 702 of the Federal Rules of Evidence, must possess specialized knowledge, be sufficiently qualified, provide information that would help a jury understand an issue, and offer reliable testimony (Conley and Moriarty 2011: 27 28). Both defense attorneys and prosecutors may employ expert witnesses. This entry provides an overview of the types of evidence that experts may be called upon to provide, the legal criteria necessary for expert testimony to be provided, information sharing among defense attorneys and prosecutors, concerns over the credibility of expert witnesses, specific examples of unethical conduct, and proposed solutions to concerns raised about expert testimony. Testimony by an expert witness may be offered in a court of law to prove or disprove the existence of a fact (Neubauer and Fradella 2011: 350). Testimony may relate to direct or circumstantial evidence. Circumstantial evidence indirectly links a suspect to a crime. For example, a mud print from a shoe left on the floor of a burglarized home may match that of a defendant. This provides only circumstantial evidence because the shoe print proves only that the shoe was at the crime scene; it does not provide concrete evidence that the defendant was even present. Nonetheless, an expert may be called upon to assess whether the mud print could have been made by a shoe owned by the defendant. Direct evidence, in contrast, concretely connects the defendant to the crime; no inference or presumption is required to draw the connection. Direct evidence may be thought of as hard evidence. For example, direct evidence of a crime may be provided by a witness who testifies that she saw a bright-orange-haired man mug a victim in broad daylight. Expert testimony is not required for such evidence; because of its nature no professional interpretations are necessary. Professional interpretations, however, may be necessary for several forms of circumstantial evidence. As noted above, an expert may be called upon to determine whether a defendant s shoe matches a print left at the crime scene. Experts may also be asked to provide testimony about other objects or materials tied to a crime scene. Such physical evidence may include bullet casings, tire tracks, fingerprints, hair, deoxyribonucleic acid (DNA), and so on. For example, an expert may help to determine the identity of a suspected burglar by matching fingerprints taken from a doorknob, window, and refrigerator in the victim s home to a database. Experts may also testify about the authenticity of documents; these may include photographs, letters, contracts, and audio-recordings or video-recordings that may connect a defendant to a crime. The best evidence rule generally requires that originals be used because contents may be too easily altered (DeSilva 1999). Provided that expert testimony will be used, a judge must also determine that relevant and trustworthy (i.e., reliable) information will be provided by the expert. Evidence is relevant if it helps one to assess the validity of a contested fact during trial. For example, a medical forensic expert s testimony would not be relevant in a case where a defendant was accused of committing a victimless offense. Evidence is reliable when one would be confident that the testimony provided would be consistent from one expert to the next. Different fingerprint experts, for example, should arrive at the same conclusion. A standard for the admissibility of expert testimony at trial was established in Frye v. United States (1923), when a federal district court ruled that polygraph evidence was inadmissible at trial The Encyclopedia of Criminology and Criminal Justice, First Edition. Edited by Jay S. Albanese John Wiley & Sons, Inc. Published 2014 by John Wiley & Sons, Inc. DOI: / wbeccj525

2 2 Expert Witness because its scientific integrity had not yet been established. Instead, the court made it clear that expert testimony would be allowed only if conclusions were based on well-recognized scientific principles: The thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs (Frye v. United States 1923). In other words, after Frye judges had to determine whether an expert s testimony would pass a general acceptance test (Bernstein 2000). The Frye standard, however, did not provide specific guidance for judges required to make such a determination. A later ruling in Daubert v. Merrell Dow Pharmaceuticals, Inc. (1993) provided greater direction for judges. More specifically, the Supreme Court stated that judges must consider whether the expert s scientific procedure could be replicated by others. Replication allows not only for conclusions to be validated, but also for inferences to be refuted by others. In addition, judges must ask whether the method has been published and subjected to professional review. Moreover, a judge must also assess the potential for expert error for any given method under consideration. Testimony should not be allowed if it is based on science that is junky (Daubert v. Merrell Dow Pharmaceuticals, Inc. 1993). Overall, an expert s testimony will be admissible if it is rooted in standards that are generally accepted by a scientific community, may be replicated, and has a small likelihood of error. When expert testimony will be used at trial, any reports, opinions, or findings produced by a given expert must be shared prior to trial. This is accomplished through a legal process called discovery; both prosecutors and defense attorneys are required to disclose whether they plan to use expert testimony (Legal Information Institute 2010). An expert, of course, will be used only if an attorney believes that his or her testimony is essential to a desired case outcome. To help make that determination, a lawyer will call upon a potential expert witness and ask for his or her opinion on case materials. A lawyer may learn about possible experts from fellow attorneys or from individuals who run social justice coalitions (Engstrom and McDonald 2011). Attorneys may also review scholarly articles or canvass universities. Or they may rely on companies dedicated to identifying expert witnesses (Mandel 1999). The expert may or may not be paid for an initial consultation, but most will likely ask for money (i.e., a retainer) upfront. Some experts will never testify at trial, but may instead be used only to help a defense attorney or a prosecutor to strategize a case (Engstrom and McDonald 2011: 286). The work produced by consulting experts is not required to be disclosed to the opposing side; only the work of experts who will actually testify must be disclosed. But attorneys may not know in advance whether they plan to put an expert on the stand. Those who testify must be credible and intelligent, able to withstand the rigors of crossexamination, and capable of explaining complex concepts to average people (Engstrom and McDonald 2011). Of course, a person who provides expert testimony should provide an objective opinion and not allow personal prejudices or bias to affect the opinions offered (Goldman 1986). Ethical standards of conduct are absolutely essential, but some may question the professional integrity of some expert witnesses. The concern over an expert s credibility is closely connected to the hired gun argument (Kousser 1985). If used, experts are hired to help a prosecutor or a defense attorney win a case. Expert witnesses, for the most part, are paid well; daily compensation ranges between $800 and $5,000 plus the costs of expenses and travel arrangements (Poynter 2007). Some experts may earn even more, depending on their level of expertise, rarity of the specialty in which testimony may be required, their status within their field of study and legal community, and how much the interested party is willing to pay (Poynter 2007). Given that experts are hired by one side, some may question whether they truly provide neutral and objective testimony. Indeed, there are examples from notorious cases where experts failed to act with integrity. For example, in 2007, a 403-page report about the problems with the Houston crime lab was released. It detailed the reexamination of 3,500 cases with forensic scientific evidence; 850 of these cases dealt with evidence for inmates who were found guilty and sentenced to terms of incarceration (Bromwich 2007). The experts who conducted the initial tests made a slew of grievous errors including serious analytical

3 Expert Witness 3 and interpretive errors that resulted in highly questionable results being reported, poor documentation, and a failure to use reasonable quality assurance measures (Bromwich 2007). In the case of Josiah Sutton, a forensics expert from the Houston crime lab testified that the DNA evidence taken from the victim was a perfect match to Sutton (Khana and McVicker 2003). Sutton was convicted and sentenced to serve 25 years in prison, but he was later exonerated after subsequent DNA tests by another expert proved that he was not the rapist. After the Sutton case, the Houston Police Department shut down its DNA laboratory and conducted an internal investigation; several employees were put on administrative leave and others resigned. The problems with expert testimony are not unique to Houston. In West Virginia, Fred S. Zain the former chief serology expert for the state was indicted for concocting evidence against innocent defendants (Clines 2001). Zain s indictment was based on a long history of complaints from falsely convicted individuals, colleagues, and the West Virginia Supreme Court about his shoddy methods. To elaborate, in 1993 the West Virginia Supreme Court reviewed 189 of Zain s cases and warned that any testimony provided by him at any time should be viewed as unreliable and, therefore, inadmissible (Clines 2001). Moreover, seven convictions relying on his testimony have been overturned upon challenge... with millions of dollars in settlements paid to those who complained of deliberate injustice (Clines 2001). Regrettably and as indicated by the examples above, junk scientists are often exposed only after the subsequent negative consequences of their testimony come to light. This is because it is difficult for jurors and judges to assess the reliability of so-called expert testimony in a courtroom since few (if any) laypersons have relevant scientific backgrounds with which to fully comprehend and, therefore, critically evaluate the complexity of the evidence presented (Wesley 1984: 679; Ivkovic and Hans 2003: 442; Danaher 2011: 210). In addition, researchers find that expert testimony unduly impresses judges and jurors, and the weight attached to such testimony is considerable (Wesley 1984). Seventy percent of the judges and lawyers surveyed in a recent poll indicated that juries accord scientific evidence more credibility than other evidence, and 75% believed that judges find scientific evidence more credible than other forms of evidence (Wesley 1984: 678). And, of the scientific evidence that jurors may hear, more weight will be given to evidence that relies on laboratory-style methods by medical doctors, chemists or toxicology experts, and firearms experts than to evidence derived from less exotic tools by psychologists, police officers, or handwriting experts (Saks and Wissler 1984: 442). Experts who provide testimony based on laboratory-style methods are more likely to be viewed as honest, competent, and credible; such perceptions mean that jurors are more inclined to agree with the testimony that such experts provide (Saks and Wissler 1984: 443). But, the perceived honesty and competence of members of a field may have nothing to do with their actual honesty or competence (Saks and Wissler 1984: 443). Unfortunately, jurors may be inclined to believe the testimony provided by expert witnesses due, in part, to biased portrayals in television crime story dramas, which lead many to believe that all experts are infallible. Indeed, scholars have discussed the CSI effect as it relates to jurors expectations that accurate forensic evidence will be presented at all criminal trials (Wheate 2010: ). Many jurors wrongly believe that scientific evidence is always 100% correct, although there is always a margin of error associated with any analysis (Radford 2010). In general, scientific evidence may be precise and superior to other types of evidence (depending on the case). However, a piece of evidence is problematic if the person who conducts the analysis is incompetent. An expert s level of competence is an extremely important consideration. Fortunately, there are several possible solutions to some of the concerns raised about the use of expert witness testimony. Perhaps the most important and cost-effective proposal for dealing with concerns over the integrity of such evidence is to assure that pretrial discovery conferences take place and that court-appointed experts are available for both sides. The pretrial conference is the starting point in dealing with complex scientific evidence because such a conference prepares attorneys for potentially complex testimony and may serve to identify those who are most competent in a particular area (Wesley 1984: 696). In cases where expert testimony will be

4 4 Expert Witness used, court-appointed experts may be provided for both defense attorneys and prosecutors in order to assure that the evidence presented will be carefully scrutinized. Another proposed solution is the creation of science courts that would handle criminal cases involving scientifically and technologically complex issues (Wesley 1984: 687). Personnel working in such a court would help judges and jurors to weigh the evidence presented by an expert. Others believe that the scientific and technological understanding of judges could be improved through specialized training courses; such training may provide guidance for judges to assess more critically whether an expert s testimony meets legal standards of admissibility (Wesley 1984: 693). Moreover, such training would help judges to better instruct jurors in the deliberation process. Proper instructions should prepare jurors to carefully assess the evidence before they may render a verdict (Doyle 1984: 639). Others argue that experts should be required to present evidence in a clear and simplified manner so that judges and jurors may easily comprehend the testimony provided. If this cannot be done, then the evidence should be excluded from consideration (Wesley 1984: 694). But such a proposal is problematic; most legal scholars believe that all relevant pieces of evidence should be presented in order for justice to prevail. The use of expert testimony has been a concern of legal scholars for a long time. Rulings about what should be considered by judges before they may allow such evidence to be presented have evolved over time from Folkes v. Chadd to Daubert v. Merrell Dow Pharmaceuticals. Judges may only allow expert testimony if they deem it to be relevant and trustworthy, and when considering scientific evidence they must determine whether it: (1) is rooted in standards that are generally accepted by a scientific community, (2) may be replicated, and (3) has a small likelihood of error. After a judge rules that expert testimony is admissible the competence of a given expert should be carefully scrutinized. But this is easier said than done; most people do not possess the requisite scientific backgrounds to critically assess the testimony provided by so-called experts and most experts are trusted to provide accurate conclusions. Unfortunately, testimony provided by junk scientists has been used to convict people wrongfully in Texas, West Virginia, and in other jurisdictions. Because of these infamous cases, proposals have been offered to minimize the likelihood that problematic testimony will be considered by judges and jurors. Some of these proposals are more realistic than others. Concerns and proposed solutions will continue to be voiced by legal scholars in the years to come amidst continuing scientific and technological advancements. These future advancements will certainly add to the complexity of the issue. SEE ALSO: Careers in Forensic Science; Discovery; Ethics and Criminal Justice Professions; Forensic Evidence; Forensic Science; Judicial Training; Witnesses, Examination of. References Anderson, P. R. (1987) Expert Witnesses: Criminologists in the Courtroom. Albany, NY: State University of New York Press. Bernstein, D. E. (2000) Frye, Frye, again: The past, present, and future of the general acceptance test. Jurimetrics 41, 385. Bromwich, M. R. (2007) Final Report of the Independent Investigator for the Houston Police Department Crime Laboratory and Property Room. Washington, DC: Fried, Frank, Harris, Shriver & Jacobson LLP. Clines, F. X. (2001) Work by expert witness is now on trial. New York Times /09/05/national/05LAB.html, accessed April 4, Conley J. M., & Moriarty, J. C. (2011) Scientific and Expert Evidence. 2nd edn. New York: Wolters Kluwer Law & Business. Danaher, J. (2011) Blind expertise and the problem of scientific evidence. The International Journal of Evidence & Proof 15, Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 US 579 (1993). De Silva, C. A. (1999) Review of selected 1998 California legislation: Evidence: California s best evidence rule repeal: Toward a greater appreciation for secondary evidence. McGeorge Law Review 30, Doyle, J. M. (1984) Applying lawyers expertise to scientific experts: some thoughts about the trial courts analysis of the prejudicial effects of admitting and excluding expert scientific testimony. William & Mary Law Review 25(6), Engstrom, R. L., & McDonald, M. P. (2011) The political scientist as expert witness. Canadian Journal of Political Science 44,

5 Expert Witness 5 Folkes v. Chadd, 99 Eng. Rep. 589 (1782). Frye v. United States, 293 F (DC Cir. 1923). Goldman, A. H. (1986) Cognitive psychologists as expert witnesses: A problem in professional ethics. Law and Human Behavior 10(1/2), Ivkovic, S. K., & Hans, V. P. (2003) Jurors evaluations of expert testimony: Judging the messenger and the message. Law & Social Inquiry 28(2), Khana, R., & McVicker, S. (2003) New DNA test casts doubt on man s 1999 rape conviction. Houston Chronicle. truthinjustice.org/sutton.htm, accessed April 4, Kousser, M. J. (1985) Are expert witnesses whores? Public Historian 6, Legal Information Institute (2010) Discovery: An Overview. Cornell University Law School. accessed April 4, Mandel, M. J. (1999) Going for the gold: Economists as expert witnesses. The Journal of Economic Perspectives 13, Neubauer, D. W., & Fradella, H. F. (2011) America s Courts and the Criminal Justice System 10th edn. Belmont, CA: Wadsworth. Poynter, D. (2007) The Expert Witness Handbook: The Techniques for the Litigation Consultant, 3rdedn. Santa Barbara, CA: Para Publishing. Radford, B. (2010) The CSI effect: How TV influences true crime. Discovery News. com/human/the-csi-effect-how-tv-influences-truecrime.htm, accessed April 4, Saks, M. J., & Wissler, R. L (1984) Legal and psychological bases of expert testimony: Surveys of the law and of jurors. Behavioral Sciences & the Law 2(4), Wesley, J. W. (1984) Scientific evidence and the question of judicial capacity. William & Mary Law Review 25(4) Wheate, R. (2010) The importance of DNA evidence to juries in criminal trials. International Journal of Evidence & Proof 14,